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#include "allocator.h"
#include "aoc.h"
#include "vec_s.h"
#include "dvec_s.h"
#include "util.h"
#include <assert.h>
#include <stdint.h>
#include <stdlib.h>
static char *
load_map(size_t *maxx, size_t *h)
{
const char *lpos, *lend;
size_t rows, cols, len;
char line[256];
char *map;
map = NULL;
rows = 0;
cols = 0;
lpos = aoc.input;
lend = lpos + aoc.input_size;
while (readtok(line, sizeof(line), '\n', &lpos, lend)) {
len = strlen(line);
if (!len) continue;
if (!cols) cols = len;
assert(len == cols);
map = realloc(map, cols * (rows + 1) + 1);
memcpy(map + cols * rows, line, cols);
rows += 1;
}
map[rows * cols] = '\0';
*maxx = cols;
*h = rows;
return map;
}
static void
print_map(char *map, size_t w, size_t h)
{
size_t y;
for (y = 0; y < h; y++)
aoc_debug("%.*s\n", w, &map[y * w]);
}
static uint64_t
map_id(char *map, size_t w, size_t h)
{
size_t x, y, b;
uint64_t id;
b = 0;
id = 0;
for (y = 0; y < h; y++) {
for (x = 0; x < w; x++) {
if (map[y * w + x] == '#')
id |= 1 << b;
b += 1;
}
}
return id;
}
static void
step(char *prev, char *next, size_t w, size_t h)
{
struct vec2i pos, npos;
size_t i, k, count;
for (pos.y = 0; (size_t) pos.y < h; pos.y++) {
for (pos.x = 0; (size_t) pos.x < w; pos.x++) {
count = 0;
for (i = 0; i < 4; i++) {
vec2i_add(&npos, &pos, &adj[i]);
if (npos.x < 0 || (size_t) npos.x >= w)
continue;
if (npos.y < 0 || (size_t) npos.y >= h)
continue;
k = (size_t) npos.y * w + (size_t) npos.x;
if (prev[k] == '#') count += 1;
}
k = (size_t) pos.y * w + (size_t) pos.x;
if (prev[k] == '#' && count != 1) {
next[k] = '.';
} else if (prev[k] == '.' && (count == 1 || count == 2)) {
next[k] = '#';
} else {
next[k] = prev[k];
}
}
}
}
void
part1(void)
{
struct dvec ids;
char *map, *next, *tmp;
uint64_t *slot, id;
size_t w, h, i;
uint64_t answer;
map = load_map(&w, &h);
next = memdup(map, w * h + 1);
dvec_init(&ids, sizeof(uint64_t), 0, &stdlib_strict_heap_allocator);
slot = dvec_add_slot(&ids);
*slot = map_id(map, w, h);
aoc_debug("INIT\n");
print_map(map, w, h);
answer = 0;
while (!answer) {
step(map, next, w, h);
tmp = map;
map = next;
next = tmp;
aoc_debug("$ %i\n", ids.len);
print_map(map, w, h);
id = map_id(map, w, h);
for (i = 0; i < ids.len; i++) {
aoc_debug("%lu vs %lu\n", id, *(uint64_t *)dvec_at(&ids, i));
if (*(uint64_t *)dvec_at(&ids, i) == id) {
answer = id;
break;
}
}
slot = dvec_add_slot(&ids);
*slot = id;
}
aoc.answer = aprintf("%lu", answer);
aoc.solution = "30446641";
dvec_deinit(&ids);
free(next);
free(map);
}
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